In this study, we firstly aim to randomly allocate screening attendee to one of the following four arms: one-day sampling with annual screening, one-day sampling with biennial screening, two-day sampling with annual screening, and two-day sampling with biennial screening. Participation rate, positive rates of FIT, detection rate for neoplasms, positive predictive value, and long-term outcome including cancer incidence and mortality will be calculated and compared among four groups.